I regularly get mixed results regarding startup time, and it's probably my biggest issue with Sublime. If I am starting it for the first time after booting my computer, it's fairly speedy. However, if my system has gone into standby for any amount of time it seems like Sublime takes quite a while to launch - sometimes updward of 20 seconds. My system isn't extremely powerful, but it's decent enough (~dual core 2.0 Ghz).

If Sublime was open when my system went into standby, it can often take 20-30 seconds to "wake up" and render on the screen. This is probably my biggest gripe. Otherwise, I still enjoy it and use it as my primary text editor.